EFFECTS OF CAPSAICIN DESENSITIZATION ON TASTE IN HUMANS

The desensitization effects on taste resulting from application of 100 or 10 ppm capsaicin, accompanied by daily testing of a capsaicin seri es (1-1000 ppm, in log steps), or the desensitization resulting from a pplication of 100 ppm capsaicin without the daily capsaicin testing, w ere investigated. The taste stimuli were three concentrations each of NaCl, sucrose, citric acid, quinine and 6-n-propylthiouracil. Followin g either type of 100 ppm desensitization, the magnitude estimates of t he two bitter tastes, in particular, and citric acid showed significan t decrements. Following 10 ppm capsaicin desensitization or an ethanol control procedure, there were no such effects. Recovery was complete in 1-3 days. It seems possible that the taste decrements are due to ef fects on both the taste and tactile components of taste, though there is a stronger case for effects on the tactile component.